I wouldn't end the interview then and there. Instead, I'd pull out a copy of my generic freelance contract, fill in my billable rate for the project after revie

I wouldn't end the interview then and there. Instead, I'd pull out a copy of my generic freelance contract, fill in my billable rate for the project after reviewing the scope, and end the interview after they refused to sign it. My opinion is that companies that think unpaid "code challenges" are a good idea don't respect my time enough as an individual to be worth it to work for. It's a signal that they're either going to have an awful work/life balance or that they are filled with unjustifiably arrogant "rockstars" in a caustic environment of petty elitism (or both). The latter signal applies especially if the company's product is some web "application" for the young-20-something set.